1. Field of the Invention
The present invention relates to flow meters and sensors for measuring the flow of a fluid through a conduit, and particularly to a gas flow surveillance device for the measurement of dynamic pressure in a gas lift flow operation, frequently used in oil drilling rigs.
2. Description of the Related Art
Many oil and gas exploration and production companies need to enhance the recovery of oil from wells that do not have sufficient pressure to produce without the aid of an artificial lift system. Typically, these companies use gas lift as the artificial lift to produce the well. Gas lift processes generally involve injecting gas down into an oil well. The gas aerates the oil and other fluid in the well, until the fluid exerts less pressure than the formation, so that the pressure exerted by the formation lifts the fluid in the oil column for removal at the well head. The gas is subsequently removed from the fluid. In order to optimize the production of oil using gas lift, it is necessary to continuously monitor flow rates, including any flow rate in the well bore.
Existing technology that may be deployed in this application includes intrusionary multiphase or mass flow meters, or non-intrusionary ultrasonic flow meters. These devices are generally far too expensive to be deployed in a production company environment.
Additionally, the intrusionary type devices usually offer an insufficient maximum working pressure for offshore applications, where a working pressure requirement of 5,000 psi or greater is required for instrumentation on a well's flow line. Other problems related to the aforementioned devices include the added burden of piping fabrication and construction, making installation cost prohibitive.
Moreover, the use of traditional differential flow measurement technology and products in a gas lift flow environment would introduce burdensome maintenance requirements due to the dirty nature of the flow stream, which would cause plugging of the sensing lines.
There exists a need to have an alternative gas lift flow surveillance device that does not introduce the aforementioned problems, yet is compatible with existing flow data acquisition technologies, such as Supervisory Control And Data Acquisition (SCADA) software running on Programmable Logic Controllers (PLCs), Remote Terminal Units (RTUs), and the like.
Thus, a gas lift flow surveillance device solving the aforementioned problems is desired.